1. Field of the Invention
The present invention relates to an original handling apparatus for separating and feeding each original from an original table to an exposure position and for outputting the exposed original from the exposure position.
2. Description of the Prior Art
In a conventional original circulation apparatus as one type of original handling apparatus, a bundle of originals to be fed are placed on an original table, and sequentially fed one by one from the uppermost or lowermost sheet by a friction pickup means arranged at the feed end side of the bundle of originals. A fed original is conveyed to a predetermined position on a platen glass, and the exposed original is returned to the original table and stacked on the unexposed originals.
In this type of apparatus, it is difficult to reliably feed original sheets one by one by the friction pickup means. When a large number of originals are stacked, no original may be fed or two or more sheets may be fed causing double or triple feed. In order to prevent this, the operator is warned not to stack originals exceeding a predetermined number (regulation number) of sheets. Thus, if the operator accidentally stacks originals exceeding this predetermined number (regulation number), the above trouble occurs and the originals may be damaged.
Moreover, when the number of stacked originals increases, the weight also increases and may cause damage to the original table.
In this type of apparatus, a circulation structure is frequently adopted. In this structure, a partition arm is placed on a bundle of originals to be picked up and fed. Output originals are sequentially stacked on the arm. When the final original is fed, the partition arm drops by its own weight. One cycle of originals is confirmed by a signal from a means for detecting the dropped arm.
When the final sheet is fed, the partition arm drops by its own weight and the dropped arm is detected to determine one cycle of originals. Thus, if the arm does not fall due to malfunction, the apparatus cannot confirm one cycle of originals and continues to operate.
In addition, originals to be handled by this type of apparatus have various sizes, e.g., B5, A4 and the like. For this reason, each time the original size is changed, the operator must move an original guide mounted on the original table in accordance with the original size. Normal original feeding can be performed only when the original guide is moved to an optimal position. However, in practice, the operator may not adjust the original guide at the optimal position before setting the originals. Then, inclined feeding or defective pickup of originals may occur. When a means for detecting such improper operation before original feed begins is incorporated, the overall mechanism becomes complex.